Pyridine compounds



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,UNI TED" STATES, PATEINTfOFFICE' .PYRIDINE ootiroUNDsf' l Wolfle Harry'Feinstone, Yonkers; alumna Friedman, New York,-N. Y amnion to 'Pyridlum Corporation, Yonkers, .N", X, a @Q'Dfltitionof New York I 3 N5 Drawing. 1 Appiiea'tionluly 25,1945;-

f Serial No. 607,080 '4c1aims.- (cine-297)" t Our invention relates to, and has for it s oba proper amount of the active bacteriostatic com-- ject, the adaptation of chemical cbmpounds that pound to accomplish its desired effectiveness, and are useful for devitaliziriarendering harmless or that, therefore, anycompound of this character innocuous bacteria, and refers particularly to such which would practically retain its bacteriostatic compounds as are. thus usefully applicable to such .5 properties irrespective of the inhibitory substances bacteria as cause tubercular infections, without present wouldbe of the highest value. v limitation however, to that particular bacterium. This property of the'compounds, included with- We have found that the therapeutically preincur invention, of being practically uninhibited pared compounds includedin my invention have in bacteriostatic eflectiveness, and especially in new, useful and unexpected bacteriostatic propbacteriostatic eifect against Myobacterium tubererties against the bacilli causing tubercular inculosis, is entirely unexpected and cannotbe predfections. i icated upon any prior knowledge relative to pre- These compounds show a marked and u'nexviously known bacteriostatic compounds, and is pected activity against Mycobacterium tuberculo of the highest importance and value in the treatsis. This action against'Mycobac'terium tubercument of infection. losis is particularly unexpected and remarkable By inhibitory substances in our specification as they are relatively without effect against other and claims, we mean those substances which prepathogenic organisms such as E. coli, staphylovent the bacteriostatic action normally manifested coccus aureus and Streptococcus pyogenes. vSub by compounds in their absence, but which do not stances, which were hitherto known to have acinhibit the bacteriostatic activities'of the comtivity against Mycobacterium tuberculosis, such pounds of our invention.

as certain sulfonamide and related compounds We have found that when adequate precautions are greatly, if not completely, inhibited in the are takento administer these compounds in such presence of biological inhibitory substances, Which a manner and with such frequency as to insure is known to account for the lack ofsufficient in a desired concentration of the respective comvivo activity of those previously known compounds in the bloodstream, they are effective in pounds. V the treatment of tuberculosis.

Some of the inhibitory substances which are j The primary object of our invention is to propresent in thehuman organism include paravide chemical compounds, which inhibit the aminobenzoic acid, serum, peptones, pus and other growth: devitalize, or render harmless Mycobacprotein degrad tion products. which have hig terium tuberculosis with or without the presence content of inhibitory substances. These inhibia of uch inhibitory. substances as peptones, serum,

' tory substances in'the lesions of tuberculosis ani'l pus, p-aminobenzoic acid, etc., without limitation other diseases which produce large amounts of to that particularbacterium. t ssu breakdown p y y important role in .Another object or our invention is to treat anithe inhibition of sulfonamide and sulfone commals and human beings, infected with tuberculopounds. As a result of this inhibitory mechanism, i by/ administering said compound in segregatt peut c t ials on'the whole faiIBd D Y- ed doses in such a manr'ier as to insure effective he c ivity f 0111 Compounds against Mycoconcentration in the blood stream.

bacterium tuberculosis is not diminished, when 40 The general formula of the compound of our p-aminobenzoic-acid, peptones, serum, pus, etc., i v nti 1 are present. We have found thatlthese compounds inhibit the'growth of various strains of tuberculosis organisms in various dilutions, so me "ro no diluted as high as one part to 25 millionsdepend r ing upon the medium .and strain of tuberc'ulosis organism used. r i l i ,in which Xis a member of the group consisting As the number 'and the proportions of these "of amino radicals, radicals hydrolyza'bie'to-aininoinhibitory substancesvaryin t tub uia 1 t, radicals and J radicals reducible to amino radie it is evident that it is impossible to administer 5o cals; R- is a member 01' he r p of Short 0118411 3 alkyl radicals having not more than two carbon atoms, and Y is a member of a group of alkyl radicals having not more than six carbon atoms. The YO-RO member is preferably in the 2 position and the X member in the 5 position. Changing the respective positions of these two members changes the activity of the compounds.

For the X of the general formula we prefer the amino group of the acylamino group. For acyl groups we may use formyl, acetyl, propionyl, etc., acid radicals.

As the animal or human body has the tendency to acetylate the free amino groups of chemical compounds, we prefer the acetyl group for the acyl group. These acetylated compounds as a rule are somewhat less toxic, but, as expected, their activity is somewhat lessened. On the other hand, the acyl groups may be hydrolyzed in the body to release the more active base. Instead of amino groups we can use compounds with nitro group as they are as a rule reduced to the amino group in the body.

For the YO-RO- group we have prepared and tested compounds with methoxyethoxy-, ethoxyethoxy-, butoxyethoxy-, groups, but it is evident that other alkoxyalkoxy compounds could be used.

From among the compounds capable of forming the YORO compounds of the above men'- tioned formula, we mention ethylene-glycolmonomethylether, ethylene glycol m'onoethylether and ethylene-glycol-monobutylether as examples of the general group which we have found of particular interest.

The following are processes for the production of some of the compounds of our invention:

Example I 5 grams sodium were dissolved in 200 ccs. ethylene glycol monomethylether, cooled to room temperature, and 31.8 grams 2-chloro, 5- nitropyridine were added. It was heated to and kept at 90100 C. under stirring for 2 hours. After standing over night, the brown colored solution was filtered from the precipitated sodium chloride, and drowned in 500 ccs. water. After cooling, the crystalline precipitate was collected, washed with ice water, and recrystallized from water to which charcoal was added. The white crystalline product is 2-methoxyethoxy, 5-nitro pyridine. 20 grams of this nitro compound were reduced to the amine in 60'ccs. water and 60 ccs. methanol with 40 grams iron filings and 2.5 cc. glacial acetic acid by refluxing under continuous stirring for 6 /2 hours. After standing over night 60 ccs. methanol and 8 ccs. of 20% solution of sodium hydroxide were added and the mixture filtered. The filter cake was washed well with methanol and the methanol distilled from the filtrate. 5 cos. of 20% sodium hydroxide solution were added to the filtrate which was then extracted with ether. The ether was distilled off and the residue was vacuum distilled. The free amine, 2-methoxyethoxy, 5-aminopyridine distills at 120-136 C. and 1.5 mm. The liquid distillate was dissolved in dry ether and the more stable dihydrochloride precipitated with dry hydrochloric acid gas.

. Example II 5 grams sodium were dissolved in 200 ccs. ethyleneglycolmonoethylether, cooled to room temperature and 32 grams 2-chloro, 5-nitropyridine were added. They reaction mixture was worked up as in Example I to obtain 2-ethoxyethoxy, 5-nitropyridine, and this was reduced to the free amine 2-ethoxyethoxy, S-aminopyridine, which boils at 129-142 C. at.0.8 mm.

Example III 3 grams 2-methoxyethoxy, 5-aminopyridine, prepared according to Example I, was dissolved in ether, refluxed with 2 cos. acetic anhydride and evaporated on the steam bath to an oily residue. A few cos. of water were added and digested on the steam bath adding sodium bicarbonate little by little until neutral reaction. On evaporation on oily residue was obtained, which became crystalline on cooling. This was dried in a desiccator, pulverized and extracted with acetone. The acetone solution was evaporated and the remaining syrup cooled for crystallization. For purification it was boiled up in methanol with charcoal and evaporated to dryness. The product is 2-methoxyethoxy, 5-acetaminopyridine.

For test organism we have used M ycobacterium tuberculosis var. hominis. The tests were conducted both in the absence and in the presence of inhibitory substances like p-aminobenzoic acid, serum, 'peptones, pus, nicotinic acid, biotin, thiaminechloride and others.

The activity of some of the compounds included in our invention against Mycobacterium tuberculosis are tabulated below. The figures indicate the highest dilution that still inhibits the growth of Mycobacterium tuberculosis, under a particular set of experimental conditions as regards inoculum, culture, etc., thereby making a comparable series.

These pyridine ethers form an oily liquid or low melting solid, some practically insoluble in water. They are unstable, color up on standing and the decomposition products so formed may be toxic and deleterious, therefore, We used their salts for testing purposes, and propose to use their salts as therapeutic agents. Pyridine, and aromatic amines form additional salts with acid. We prefer to use their hydrochlorides, formed with the addition of hydrochloric acid. But we can also use the additional salts formed with sulfuric, nitric, acetic, lactic, butyric, citric, tartaric, succinic, benzoic, salicyclic and other acids.

The compounds of our invention, therefore, present highly valuable and unexpected bacteriostatic properties especially against such bacteria as cause tubercular infections.

We do not confine ourselves to the specific limitations mentioned, as these are given solely for the purpose of clearly describing our invention as set forth herein.

What we claim is: 1. Compounds having bacteriostatic properties, and having the general formula:

of alkyl radicals having not more than 6 carbon atoms. and their salts.

2. Compounds having bacteriostatic properties, and having the formula 2-methoxyethoxy. 5-aminopyridine and its salts.

3. Compounds having bacteriostatic properties, and having the formula 2-ethoxyethoxy, 5- aminopyridine and its salts.

4. Compounds having bacteriostatic properties, and having the formula 2-butoxyethoxy, 5- aminopyridine and its salts.

woman HARRY mmsromz. mums n FRIEDMAN. 

